<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        
    </style>
</head>
<body>
    
</body>
<script>
    var arr = [3];
    var arr2 = new Array(3);

    console.log(arr);
    console.log(arr.length);
    console.log(arr2);
    console.log(arr2.length);

    console.log(arr2 === arr);
</script>
</html>